drivers/net/wireless/wl1251/tx.c

   1 /*
   2  * This file is part of wl1251
   3  *
   4  * Copyright (c) 1998-2007 Texas Instruments Incorporated
   5  * Copyright (C) 2008 Nokia Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19  * 02110-1301 USA
  20  *
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25
  26 #include "wl1251.h"
  27 #include "reg.h"
  28 #include "tx.h"
  29 #include "ps.h"
  30 #include "io.h"
  31 #include "event.h"
  32
  33 static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
  34 {
  35         int used, data_in_count;
  36
  37         data_in_count = wl->data_in_count;
  38
  39         if (data_in_count < data_out_count)
  40                 /* data_in_count has wrapped */
  41                 data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
  42
  43         used = data_in_count - data_out_count;
  44
  45         WARN_ON(used < 0);
  46         WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
  47
  48         if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
  49                 return true;
  50         else
  51                 return false;
  52 }
  53
  54 int wl1251_tx_path_status(struct wl1251 *wl)
  55 {
  56         u32 status, addr, data_out_count;
  57         bool busy;
  58
  59         addr = wl->data_path->tx_control_addr;
  60         status = wl1251_mem_read32(wl, addr);
  61         data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
  62         busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
  63
  64         if (busy)
  65                 return -EBUSY;
  66
  67         return 0;
  68 }
  69
  70 static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
  71 {
  72         int i;
  73
  74         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
  75                 if (wl->tx_frames[i] == NULL) {
  76                         wl->tx_frames[i] = skb;
  77                         return i;
  78                 }
  79
  80         return -EBUSY;
  81 }
  82
  83 static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
  84                               struct ieee80211_tx_info *control, u16 fc)
  85 {
  86         *(u16 *)&tx_hdr->control = 0;
  87
  88         tx_hdr->control.rate_policy = 0;
  89
  90         /* 802.11 packets */
  91         tx_hdr->control.packet_type = 0;
  92
  93         if (control->flags & IEEE80211_TX_CTL_NO_ACK)
  94                 tx_hdr->control.ack_policy = 1;
  95
  96         tx_hdr->control.tx_complete = 1;
  97
  98         if ((fc & IEEE80211_FTYPE_DATA) &&
  99             ((fc & IEEE80211_STYPE_QOS_DATA) ||
 100              (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
 101                 tx_hdr->control.qos = 1;
 102 }
 103
 104 /* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
 105 #define MAX_MSDU_SECURITY_LENGTH      16
 106 #define MAX_MPDU_SECURITY_LENGTH      16
 107 #define WLAN_QOS_HDR_LEN              26
 108 #define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
 109                                        WLAN_QOS_HDR_LEN)
 110 #define HW_BLOCK_SIZE                 252
 111 static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
 112 {
 113         u16 payload_len, frag_threshold, mem_blocks;
 114         u16 num_mpdus, mem_blocks_per_frag;
 115
 116         frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
 117         tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
 118
 119         payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
 120
 121         if (payload_len > frag_threshold) {
 122                 mem_blocks_per_frag =
 123                         ((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
 124                          HW_BLOCK_SIZE) + 1;
 125                 num_mpdus = payload_len / frag_threshold;
 126                 mem_blocks = num_mpdus * mem_blocks_per_frag;
 127                 payload_len -= num_mpdus * frag_threshold;
 128                 num_mpdus++;
 129
 130         } else {
 131                 mem_blocks_per_frag = 0;
 132                 mem_blocks = 0;
 133                 num_mpdus = 1;
 134         }
 135
 136         mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
 137
 138         if (num_mpdus > 1)
 139                 mem_blocks += min(num_mpdus, mem_blocks_per_frag);
 140
 141         tx_hdr->num_mem_blocks = mem_blocks;
 142 }
 143
 144 static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
 145                               struct ieee80211_tx_info *control)
 146 {
 147         struct tx_double_buffer_desc *tx_hdr;
 148         struct ieee80211_rate *rate;
 149         int id;
 150         u16 fc;
 151
 152         if (!skb)
 153                 return -EINVAL;
 154
 155         id = wl1251_tx_id(wl, skb);
 156         if (id < 0)
 157                 return id;
 158
 159         fc = *(u16 *)skb->data;
 160         tx_hdr = (struct tx_double_buffer_desc *) skb_push(skb,
 161                                                            sizeof(*tx_hdr));
 162
 163         tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
 164         rate = ieee80211_get_tx_rate(wl->hw, control);
 165         tx_hdr->rate = cpu_to_le16(rate->hw_value);
 166         tx_hdr->expiry_time = cpu_to_le32(1 << 16);
 167         tx_hdr->id = id;
 168
 169         tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
 170
 171         wl1251_tx_control(tx_hdr, control, fc);
 172         wl1251_tx_frag_block_num(tx_hdr);
 173
 174         return 0;
 175 }
 176
 177 /* We copy the packet to the target */
 178 static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
 179                                  struct ieee80211_tx_info *control)
 180 {
 181         struct tx_double_buffer_desc *tx_hdr;
 182         int len;
 183         u32 addr;
 184
 185         if (!skb)
 186                 return -EINVAL;
 187
 188         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 189
 190         if (control->control.hw_key &&
 191             control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 192                 int hdrlen;
 193                 __le16 fc;
 194                 u16 length;
 195                 u8 *pos;
 196
 197                 fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
 198                 length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
 199                 tx_hdr->length = cpu_to_le16(length);
 200
 201                 hdrlen = ieee80211_hdrlen(fc);
 202
 203                 pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
 204                 memmove(pos, pos + WL1251_TKIP_IV_SPACE,
 205                         sizeof(*tx_hdr) + hdrlen);
 206         }
 207
 208         /* Revisit. This is a workaround for getting non-aligned packets.
 209            This happens at least with EAPOL packets from the user space.
 210            Our DMA requires packets to be aligned on a 4-byte boundary.
 211         */
 212         if (unlikely((long)skb->data & 0x03)) {
 213                 int offset = (4 - (long)skb->data) & 0x03;
 214                 wl1251_debug(DEBUG_TX, "skb offset %d", offset);
 215
 216                 /* check whether the current skb can be used */
 217                 if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
 218                         struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
 219                                                                  GFP_KERNEL);
 220
 221                         if (unlikely(newskb == NULL)) {
 222                                 wl1251_error("Can't allocate skb!");
 223                                 return -EINVAL;
 224                         }
 225
 226                         tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
 227
 228                         dev_kfree_skb_any(skb);
 229                         wl->tx_frames[tx_hdr->id] = skb = newskb;
 230
 231                         offset = (4 - (long)skb->data) & 0x03;
 232                         wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
 233                 }
 234
 235                 /* align the buffer on a 4-byte boundary */
 236                 if (offset) {
 237                         unsigned char *src = skb->data;
 238                         skb_reserve(skb, offset);
 239                         memmove(skb->data, src, skb->len);
 240                         tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 241                 }
 242         }
 243
 244         /* Our skb->data at this point includes the HW header */
 245         len = WL1251_TX_ALIGN(skb->len);
 246
 247         if (wl->data_in_count & 0x1)
 248                 addr = wl->data_path->tx_packet_ring_addr +
 249                         wl->data_path->tx_packet_ring_chunk_size;
 250         else
 251                 addr = wl->data_path->tx_packet_ring_addr;
 252
 253         wl1251_mem_write(wl, addr, skb->data, len);
 254
 255         wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
 256                      "queue %d", tx_hdr->id, skb, tx_hdr->length,
 257                      tx_hdr->rate, tx_hdr->xmit_queue);
 258
 259         return 0;
 260 }
 261
 262 static void wl1251_tx_trigger(struct wl1251 *wl)
 263 {
 264         u32 data, addr;
 265
 266         if (wl->data_in_count & 0x1) {
 267                 addr = ACX_REG_INTERRUPT_TRIG_H;
 268                 data = INTR_TRIG_TX_PROC1;
 269         } else {
 270                 addr = ACX_REG_INTERRUPT_TRIG;
 271                 data = INTR_TRIG_TX_PROC0;
 272         }
 273
 274         wl1251_reg_write32(wl, addr, data);
 275
 276         /* Bumping data in */
 277         wl->data_in_count = (wl->data_in_count + 1) &
 278                 TX_STATUS_DATA_OUT_COUNT_MASK;
 279 }
 280
 281 static void enable_tx_for_packet_injection(struct wl1251 *wl)
 282 {
 283         int ret;
 284
 285         ret = wl1251_cmd_join(wl, BSS_TYPE_STA_BSS, wl->channel,
 286                               wl->beacon_int, wl->dtim_period);
 287         if (ret < 0) {
 288                 wl1251_warning("join failed");
 289                 return;
 290         }
 291
 292         ret = wl1251_event_wait(wl, JOIN_EVENT_COMPLETE_ID, 100);
 293         if (ret < 0) {
 294                 wl1251_warning("join timeout");
 295                 return;
 296         }
 297
 298         wl->joined = true;
 299 }
 300
 301 /* caller must hold wl->mutex */
 302 int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 303 {
 304         struct ieee80211_tx_info *info;
 305         int ret = 0;
 306         u8 idx;
 307
 308         info = IEEE80211_SKB_CB(skb);
 309
 310         if (info->control.hw_key) {
 311                 if (unlikely(wl->monitor_present))
 312                         return -EINVAL;
 313
 314                 idx = info->control.hw_key->hw_key_idx;
 315                 if (unlikely(wl->default_key != idx)) {
 316                         ret = wl1251_acx_default_key(wl, idx);
 317                         if (ret < 0)
 318                                 return ret;
 319                 }
 320         }
 321
 322         /* Enable tx path in monitor mode for packet injection */
 323         if ((wl->vif == NULL) && !wl->joined)
 324                 enable_tx_for_packet_injection(wl);
 325
 326         ret = wl1251_tx_path_status(wl);
 327         if (ret < 0)
 328                 return ret;
 329
 330         ret = wl1251_tx_fill_hdr(wl, skb, info);
 331         if (ret < 0)
 332                 return ret;
 333
 334         ret = wl1251_tx_send_packet(wl, skb, info);
 335         if (ret < 0)
 336                 return ret;
 337
 338         wl1251_tx_trigger(wl);
 339
 340         return ret;
 341 }
 342
 343 void wl1251_tx_work(struct work_struct *work)
 344 {
 345         struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 346         struct sk_buff *skb;
 347         bool woken_up = false;
 348         int ret;
 349
 350         mutex_lock(&wl->mutex);
 351
 352         if (unlikely(wl->state == WL1251_STATE_OFF))
 353                 goto out;
 354
 355         while ((skb = skb_dequeue(&wl->tx_queue))) {
 356                 if (!woken_up) {
 357                         ret = wl1251_ps_elp_wakeup(wl);
 358                         if (ret < 0)
 359                                 goto out;
 360                         woken_up = true;
 361                 }
 362
 363                 ret = wl1251_tx_frame(wl, skb);
 364                 if (ret == -EBUSY) {
 365                         skb_queue_head(&wl->tx_queue, skb);
 366                         goto out;
 367                 } else if (ret < 0) {
 368                         dev_kfree_skb(skb);
 369                         goto out;
 370                 }
 371         }
 372
 373 out:
 374         if (woken_up)
 375                 wl1251_ps_elp_sleep(wl);
 376
 377         mutex_unlock(&wl->mutex);
 378 }
 379
 380 static const char *wl1251_tx_parse_status(u8 status)
 381 {
 382         /* 8 bit status field, one character per bit plus null */
 383         static char buf[9];
 384         int i = 0;
 385
 386         memset(buf, 0, sizeof(buf));
 387
 388         if (status & TX_DMA_ERROR)
 389                 buf[i++] = 'm';
 390         if (status & TX_DISABLED)
 391                 buf[i++] = 'd';
 392         if (status & TX_RETRY_EXCEEDED)
 393                 buf[i++] = 'r';
 394         if (status & TX_TIMEOUT)
 395                 buf[i++] = 't';
 396         if (status & TX_KEY_NOT_FOUND)
 397                 buf[i++] = 'k';
 398         if (status & TX_ENCRYPT_FAIL)
 399                 buf[i++] = 'e';
 400         if (status & TX_UNAVAILABLE_PRIORITY)
 401                 buf[i++] = 'p';
 402
 403         /* bit 0 is unused apparently */
 404
 405         return buf;
 406 }
 407
 408 static void wl1251_tx_packet_cb(struct wl1251 *wl,
 409                                 struct tx_result *result)
 410 {
 411         struct ieee80211_tx_info *info;
 412         struct sk_buff *skb;
 413         int hdrlen;
 414         u8 *frame;
 415
 416         skb = wl->tx_frames[result->id];
 417         if (skb == NULL) {
 418                 wl1251_error("SKB for packet %d is NULL", result->id);
 419                 return;
 420         }
 421
 422         info = IEEE80211_SKB_CB(skb);
 423
 424         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 425             (result->status == TX_SUCCESS))
 426                 info->flags |= IEEE80211_TX_STAT_ACK;
 427
 428         info->status.rates[0].count = result->ack_failures + 1;
 429         wl->stats.retry_count += result->ack_failures;
 430
 431         /*
 432          * We have to remove our private TX header before pushing
 433          * the skb back to mac80211.
 434          */
 435         frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 436         if (info->control.hw_key &&
 437             info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 438                 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 439                 memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 440                 skb_pull(skb, WL1251_TKIP_IV_SPACE);
 441         }
 442
 443         wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 444                      " status 0x%x (%s)",
 445                      result->id, skb, result->ack_failures, result->rate,
 446                      result->status, wl1251_tx_parse_status(result->status));
 447
 448
 449         ieee80211_tx_status(wl->hw, skb);
 450
 451         wl->tx_frames[result->id] = NULL;
 452 }
 453
 454 /* Called upon reception of a TX complete interrupt */
 455 void wl1251_tx_complete(struct wl1251 *wl)
 456 {
 457         int i, result_index, num_complete = 0, queue_len;
 458         struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 459         unsigned long flags;
 460
 461         if (unlikely(wl->state != WL1251_STATE_ON))
 462                 return;
 463
 464         /* First we read the result */
 465         wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 466                             result, sizeof(result));
 467
 468         result_index = wl->next_tx_complete;
 469
 470         for (i = 0; i < ARRAY_SIZE(result); i++) {
 471                 result_ptr = &result[result_index];
 472
 473                 if (result_ptr->done_1 == 1 &&
 474                     result_ptr->done_2 == 1) {
 475                         wl1251_tx_packet_cb(wl, result_ptr);
 476
 477                         result_ptr->done_1 = 0;
 478                         result_ptr->done_2 = 0;
 479
 480                         result_index = (result_index + 1) &
 481                                 (FW_TX_CMPLT_BLOCK_SIZE - 1);
 482                         num_complete++;
 483                 } else {
 484                         break;
 485                 }
 486         }
 487
 488         queue_len = skb_queue_len(&wl->tx_queue);
 489
 490         if ((num_complete > 0) && (queue_len > 0)) {
 491                 /* firmware buffer has space, reschedule tx_work */
 492                 wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
 493                 ieee80211_queue_work(wl->hw, &wl->tx_work);
 494         }
 495
 496         if (wl->tx_queue_stopped &&
 497             queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
 498                 /* tx_queue has space, restart queues */
 499                 wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
 500                 spin_lock_irqsave(&wl->wl_lock, flags);
 501                 ieee80211_wake_queues(wl->hw);
 502                 wl->tx_queue_stopped = false;
 503                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 504         }
 505
 506         /* Every completed frame needs to be acknowledged */
 507         if (num_complete) {
 508                 /*
 509                  * If we've wrapped, we have to clear
 510                  * the results in 2 steps.
 511                  */
 512                 if (result_index > wl->next_tx_complete) {
 513                         /* Only 1 write is needed */
 514                         wl1251_mem_write(wl,
 515                                          wl->data_path->tx_complete_addr +
 516                                          (wl->next_tx_complete *
 517                                           sizeof(struct tx_result)),
 518                                          &result[wl->next_tx_complete],
 519                                          num_complete *
 520                                          sizeof(struct tx_result));
 521
 522
 523                 } else if (result_index < wl->next_tx_complete) {
 524                         /* 2 writes are needed */
 525                         wl1251_mem_write(wl,
 526                                          wl->data_path->tx_complete_addr +
 527                                          (wl->next_tx_complete *
 528                                           sizeof(struct tx_result)),
 529                                          &result[wl->next_tx_complete],
 530                                          (FW_TX_CMPLT_BLOCK_SIZE -
 531                                           wl->next_tx_complete) *
 532                                          sizeof(struct tx_result));
 533
 534                         wl1251_mem_write(wl,
 535                                          wl->data_path->tx_complete_addr,
 536                                          result,
 537                                          (num_complete -
 538                                           FW_TX_CMPLT_BLOCK_SIZE +
 539                                           wl->next_tx_complete) *
 540                                          sizeof(struct tx_result));
 541
 542                 } else {
 543                         /* We have to write the whole array */
 544                         wl1251_mem_write(wl,
 545                                          wl->data_path->tx_complete_addr,
 546                                          result,
 547                                          FW_TX_CMPLT_BLOCK_SIZE *
 548                                          sizeof(struct tx_result));
 549                 }
 550
 551         }
 552
 553         wl->next_tx_complete = result_index;
 554         wl->last_io_jiffies = jiffies;
 555 }
 556
 557 /* caller must hold wl->mutex */
 558 void wl1251_tx_flush(struct wl1251 *wl)
 559 {
 560         int i;
 561         struct sk_buff *skb;
 562         struct ieee80211_tx_info *info;
 563
 564         /* TX failure */
 565 /*      control->flags = 0; FIXME */
 566
 567         while ((skb = skb_dequeue(&wl->tx_queue))) {
 568                 info = IEEE80211_SKB_CB(skb);
 569
 570                 wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 571
 572                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 573                                 continue;
 574
 575                 ieee80211_tx_status(wl->hw, skb);
 576         }
 577
 578         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 579                 if (wl->tx_frames[i] != NULL) {
 580                         skb = wl->tx_frames[i];
 581                         info = IEEE80211_SKB_CB(skb);
 582
 583                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 584                                 continue;
 585
 586                         ieee80211_tx_status(wl->hw, skb);
 587                         wl->tx_frames[i] = NULL;
 588                 }
 589 }